The present invention relates to liquid compositions which contain a dichloromonofluoroethane as a solvent and at least one agent with release effective properties, to the use of such compositions, and to a process for their preparation.
Today, in many areas of industry which involve working steps such as casting, molding, pressing etc.,--for instance in the production and processing of plastics, foamed materials, building materials, rubber articles, tires, metals, glasses, ceramic products, etc.--release agents, lubricants or parting agents are required. The term "release agents" refers to solid or liquid films which reduce the adhesive forces between two adjoining surfaces, i.e. prevent them from sticking together. "Lubricants" are additives for plastic compositions, such as press molding compositions and injection molding compositions. They are needed to make the fillers slide more easily and hence to make the molding compositions easier to deform. The release agents, lubricants and parting agents contain release effective constituents, for instance in the form of dry powders, dry films or wet films, pastes, burnt-in films, solutions or dispersions. One special form is represented by the so-called internal release agents, which are mixed into material to be removed from a mold and which either become enriched on the surface or cause more rapid curing of the surface, so that no bonding occurs between the mold wall and molded article.
In many cases, in the above working steps the residues of the agent with release effective properties must be removed from the mold from time to time by means of solvents. Usually solvents such as hydrocarbons and chlorohydrocarbons are used to clean the molds, the former constituting a fire risk, and the latter causing skin irritations.
According to a process disclosed in U.S. Pat. No. 4,028,120, a mold release agent for the production of molded rubber products and the molding of foamed polyurethane materials is known. The mold release composition used therein contains paraffin wax, lamp oil and sodium soaps of tall oil acids in a paraffinic base oil. The mold release agent used must be soluble or emulsifiable in water in order to enable the mold release agent to be removed from the molded product by spraying or washing with warm water.
In U.S. Pat. No. 4,746,463 (=DE-OS 33 35 870), the preparation of special wax derivatives is described which can be used, for instance, as constituents of release agents, but in particular as cooling lubricants, whereby the fluorochlorohydrocarbons: trichloromonofluoromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,1,2,2-tetrachlorodifluoroethane, tetrachloromonofluoroethane and/or trichlorodifluoroethane are listed as suitable solvents.